Worst air pollution St Just, today and tomorrow

Today (9 August): Air quality in St Just is fair. AQI and O3 are fair; PM2.5, PM10, NO2, SO2, CO, HCHO, and PM1 are good. Pollution peaks around 1:00 PM (O3: 37.3/100).
Tomorrow (10 August 2026): Air quality in St Just is fair. All pollutants stay as today. Pollution peaks around 12:00 AM (O3: 28.0/100). Airmine updates local air quality forecasts four times daily.

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Developed with support from the European Space Agency (ESA)’s Business Applications and Space Solutions (BASS) team

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Traffic on the M40 is the most significant local emissions source, especially at peak times. The air quality picture in St Just reflects a typical Cornwall town, with traffic emissions and local commercial activity as key contributors. Easterly winds usually ensure decent dispersal, so levels generally stay within the moderate range typical of UK towns.

Today - 9 August | Pollution peaks at 13:00

AQI:

Fair

37.3/100

PM2.5 (fine particles):

Good

14.3/100

PM10 (coarse particles):

Good

5.4/100

NO2 (nitrogen dioxide):

Good

15.5/100

O3 (ozone):

Fair

37.3/100

SO2 (sulfur dioxide):

Good

2.0/100

CO (carbon monoxide):

Good

0.0/100

HCHO (formaldehyde):

Good

7.3/100

PM1 (ultrafine particles):

Good

10.0/100

Levels show the poorest local air quality during the day

Tomorrow - 10 August | Pollution peaks at 00:00

AQI:

Fair

28.0/100

PM2.5 (fine particles):

Good

12.5/100

PM10 (coarse particles):

Good

5.1/100

NO2 (nitrogen dioxide):

Good

11.6/100

O3 (ozone):

Fair

28.0/100

SO2 (sulfur dioxide):

Good

1.7/100

CO (carbon monoxide):

Good

0.0/100

HCHO (formaldehyde):

Good

2.1/100

PM1 (ultrafine particles):

Good

7.3/100

Frequently Asked Questions

Is air quality bad in St Just right now?

On 9 August 2026, overall air quality in St Just is fair. AQI is the main air quality indicator at 37.3/100. Pollution peaks around 1:00 PM (O3: 37.3/100).

Will air quality be worse tomorrow in St Just?

On 10 August 2026, air quality conditions in St Just will be similar to today, with AQI forecast at fair at 28.0/100. Pollution peaks around 12:00 AM (O3: 28.0/100).

When is air pollution at its worst in St Just?

Ask a local in St Just and they'll tell you air quality changes noticeably from season to season. Come summer, it's ozone rather than particulates that's the bigger concern, especially on still, sunny days. In deep winter, a lack of wind lets M40 traffic fumes and woodsmoke settle instead of blowing through. Most of spring and autumn stays fairly steady, right in the middle of those two extremes.

Are air quality levels in St Just based on measurements or forecasts?

It is forecasts derived by downscaling forecasts provided by EU’s Copernicus Atmosphere Monitoring Service (CAMS) by taking into account local conditions such as traffic patterns. CAMS bases its forecast on satellite measurements of particles and chemical compounds in the atmosphere. Airmine’s services were developed with support from the European Space Agency (ESA)’s Business Applications and Space Solutions (BASS) team.

Why doesn’t the forecast always reflect wildfire impacts?

Airmine’s forecast uses CAMS (Copernicus Atmosphere Monitoring Service) as its background atmospheric model. While CAMS includes wildfire emissions, these are derived from satellite observations and are not available in real time. During rapidly evolving wildfire events, there may therefore be a delay before increased emissions are incorporated into the model. As a result, the forecast may temporarily underestimate PM₂.₅ and other pollutants associated with wildfire smoke.

During rapidly evolving wildfire events, CAMS may lag by approximately 1–2 days before increased wildfire emissions are fully represented, which can lead to temporary underestimation of PM₂.₅ concentrations in Airmine’s forecast.

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Data provided by Airmine — Last update: 9 August 2026 at 20:27 CEST (Data is updated four times daily.)

This forecast is produced independently using Airmine's own atmospheric data and models.

Unless explicitly made clear, the content on this site has not been paid for by external organisations and is Airmine's sole responsibility.

Disclaimer: Forecasts are provided for informational purposes only and should not be relied upon as medical advice. Actual pollen and air quality conditions may vary from the forecast. If you have allergies, asthma, or another medical condition, consult a healthcare professional. Please see our Terms of Service for important information about limitations of liability.

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